MOSAIC (Phase A)

The Multi-Object Spectrograph

Undergoing Phase A study

The Multi-Object Spectrograph, also known as MOSAIC, is a proposed instrument for ESO’s forthcoming Extremely Large Telescope (ELT). MOSAIC is currently in the initial project stage known as Phase A. The study contract was signed at the Paris Observatory on 18 March 2016 by ESO and the CNRS–INSU, the leading technical institute in the MOSAIC consortium. The consortium includes institutions from five countries (France, United Kingdom, The Netherlands, Brazil and Germany) with six associated partners (Austria, Finland, Italy, Portugal, Spain and Sweden).

MOSAIC will provide the ELT with the powerful ability to obtain visible and near-infrared spectroscopy of large samples of astronomical objects, improving upon ESO’s current facilities. It will provide unprecedented observations of objects ranging from stars at the very heart of the Milky Way to the most distant galaxies at the edge of the observable Universe. These future observations will allow astronomers to trace the growth of galaxies and the distribution of matter from shortly after the Big Bang to the present day.

François Hammer, Principal Investigator for MOSAIC, explains: “MOSAIC will be the only ELT instrument able to obtain the sample sizes needed for significant progress in cosmology, extragalactic and galactic science, delivering spectra of a significant number of targets among the thousands included in one exposure with the ELT. In particular, MOSAIC will provide a world-leading and unique capability for spectroscopic follow-up of the most distant galaxies in the Universe, exploiting the legacy of future space missions”.

MOSAIC is being designed as a multi-purpose instrument for the ELT to be used for a broad range of scientific cases. MOSAIC aims to combine the advantages of a highly-multiplexed instrument targeting numerous unresolved sources with an instrument that can resolve sources at high spatial resolution using integral-field units.